


Cup o’ Gast

by Madlyinlov3onda



Category: Undertale (Video Game)
Genre: Reader-Insert, Self-Insert
Language: English
Status: Completed
Published: 2017-05-12
Updated: 2017-05-12
Packaged: 2018-10-30 20:43:20
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,790
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10884567
Author URL: https://archiveofourown.org/users/Madlyinlov3onda/pseuds/Madlyinlov3onda
Summary: Reader helps a friend pet-sit a "strange pet" until they can find a home... Reader wasn't told miniature skeletons could be pets.





	Cup o’ Gast

**Author's Note:**

> This was a $20 “Tiny Gaster” Commission for vhutch88-blog on tumblr
> 
> If you are interested in commissioning me, please send me a Message or an Ask through tumblr! (Messages are preferred, sometimes I don't get Asks.) Commissions can be anything- continuations of previous fics, something new entirely, nsfw, Overwatch, Undertale, whatever! Just let me know and I’ll see if I can do!
> 
>  
> 
> This fic is unrelated to Sans Days, however I did receive some coffee donations, and if I get around 5 more coffees I’ll finish up the latest chapter for you guys. 
> 
> (In case you are not following me on Tumblr, I am currently trying to make some money so I can buy some Overwatch things. Please feel free to hit me up if you want to donate or commission me!)

 

“You almost there?”

“Yeah, I’m pulling into the driveway now.” You replied to your friend through the phone, putting your car into park.

“Thank you again so much. The key is under the cactus plant, just let yourself in—the box should be left of the door,” she explained, and you nodded despite not being able to see her in the first place. You grabbed the small fake cactus plant and saw the flowery key underneath.

“You just really like flowers, huh?” You muttered, partially forgetting you were still on the phone with her.

“Yes, it’s not my fault I kill everything I touch—Oh… speaking of which…” She grew quiet as you wiggled the key into the lock, taking a moment to finally open the door. “So I know I told you that I needed help looking after a pet until I find a solid home for it, but uhhh… It’s not exactly a… a classic pet.”

You rolled your eyes at the phone. “I’m sure I’ve handled stranger. I’ve dealt with all sorts of bunnies, dogs, cats, birds, chinchillas—I’ll be fine.” Huh, she must have cleaned recently. You looked around the very organized living room, till you saw one of the classic cardboard boxes with holes on top to the left of you.

“I know you will be, but it uh, it’s been through a lot—especially with its past owner dying and all, and I just want you to be ready.” You shrugged off what she said and knelt next to the box, opening it. “You were quick to agree to help but you didn’t even ask—”

“Hey, Sue?” You interrupted, looking at the “pet” in the box.

“Yeah?”

“What the fuck is this?” you asked, looking at the… small skeleton? It was sitting in the corner of the box, knees to its chest. It barely glanced at you with glowing halos before staring back at the ground. If it wasn’t for the slight movement you would have thought it was some sort of doll. A doll with a broken face, it would appear. Two cracks led in different directions from each eye socket, making your confusion falter into concern for a moment.

“It’s—ah… it’s a skeleton, I think? Mable had a lot of really weird pets, most of her friends ended up taking most of them but he’s the last one that didn’t get called on. I think its name starts with a G? I keep forgetting it,” your friend explained, but most of her words went in one ear and out the other as you stared at the small skeleton man. He had what looked like a fancy suit on, though it looked like it was in constant motion, and occasionally appeared to gain weight before sucking itself back in. It was almost hypnotizing.

“What…” You tore your eyes away from the creature, paying more attention to the conversation. “Sue, I’ve literally never seen this kind of ‘pet’ before. I was expecting a hairless hamster or something. What am I supposed to feed it? Is there even a care sheet for this sort of…thing?” You stood up, pacing around the living room.

“Oh, it’s super easy to take care of, trust me! They are just like… tiny people! They can talk—well, most of them—and take care of themselves for the most part. You just have to keep them company and make sure they don’t hurt themselves. Honestly I’d be watching him myself if I was going to be home. Like I said, I left in a rush this morning and forgot about him…”

“Is everything alright with you? I’ve literally never witnessed you forget anything before and I think that’s the third time you said you forgot something today.” You grew concerned for your friend, glancing back at the box.

“I think it’s just the skeleton. Mabel’s pets sometimes have… quirks. You don’t have to worry about it too much though. I know it’s a lot to ask, but are you still willing to watch him for a few days? I’m going to be out of town and he just lost his previous owner… I’ll double your usual pet sitting wage!” Normally you wouldn’t ask that, but more likely than not Sue would end up giving a massive tip anyway. You knew she could easily afford it, at least.

You thought a moment. Sure, this thing is nothing like any other pet you watched, but you really could use the money right now. “Okay, I can watch him. Is there anything else I should grab from your place?” You heard a sigh of relief from the other end.

“No, I didn’t get anything from Mabel’s other than the skeleton. Like I said, you just need to treat them like a tiny person. They don’t need any special food, so you can just cut a bite out of whatever you would eat and give it to them.”

“Okay… I’ll take him home now. I’ll call you if I need anything.” You hesitated, glancing at the small skeleton again.

“Sure thing! The most important thing is to make sure he isn’t alone for too long. He’s one of the quieter ones, so I’m not exactly sure how he’s handling…everything. But yeah! Feel free to message me whenever! I’ll be a little busy but I’ll get back to you when I can.”

“Have fun with your meetings.” You hung up the call and walked back to the box, seeing the skeleton not acknowledge your existence at all. “Hey, buddy, you’re gonna live with me for a little while, okay?” you asked, though if he heard you, he made no motion for it. Did he even have ears?

You waited a moment before closing the box again, and bringing it back to your car. You made sure the drive home wasn’t too loud for the… skeleton, keeping the volume of the radio much lower than you usually have it. You tried to talk a little bit, how you usually do when you bring dogs to your place, but it was different knowing maybe this pet could understand the “Almost there!”s you said.

When you finally got home you made sure to announce it, being careful not to jostle the box too much on your way inside. You made your way to the couch, carefully placing the box on the coffee table, and opened it. The skeleton startled you, for some reason you already forgot what he looked like, but you quickly shook it off and watched him carefully.

“Hey there, buddy, how’re you doing?” You asked, trying to get his attention. The skeleton still had his knees to his chest, but his eye lights followed you. You licked your lips. “Uh…I’m going to take you out of the box now, alright?” You waited for a response, but he simply blinked.

“Okay, here I go.” You slowly put your hands in the box, attempting to cup around his small body. At the touch his suit expanded and you could swear he was melting. You pulled your hands away from him quickly, feeling and seeing the dark stickiness cling on your hands for a moment before being pulled back into a normal-ish body. “O-oh! I…I’m sorry?” You half asked, but the skeleton didn’t do anything. It did look like it was sweating…maybe it was stressed. It was sitting in the corner of the box, and cats tended to do that to feel more secure and protected from the sides. You needed to keep an eye on him, but if there was a way he could be surrounded by something—oh! “One second,” you quickly told him, making sure he wasn’t going to move.

You got up from the couch and went to your kitchen, digging through the cup cabinet until you found a stray glencairn that you’ve never used before. It might be a tight fit… but you had bigger cups you could use if this even seemed like it was going to work out. You brought the glass back and showed the small skeleton. “Here, I’m going to, uh, put you in this, okay? That way I can carry you around and you don’t have to worry about me touching you,” you explained, still not sure if he could understand.

Accepting the fact you wouldn’t be getting much of a response out of him, you tilted the glass and brought it close to him, using your other hand to slowly cup the other side of him. His body expanded again, sticking to your hand, but you continued to scoop him into the cup a little slower. He clung to your hand for a moment, the chilliness of his… slime? Whatever it was, it sent a shiver up your spine, before he finally let go and settled in the glass.

He looked around in the glass a moment, before his body lost all form of…well, form.

He was melting.

The skeleton deformed and collapsed into a black puddle in the cup and you frantically scrambled to grab your phone. Your fingers were on auto-pilot as they hit Sue’s number, and you felt your breathing speed up as the phone rang. You couldn’t draw your eyes away from the puddle of a creature in your glass.

Ring… Ring… “Yeah?”

“IT MELTED,” you shouted, realizing how bad you were shaking. You’ve been home less than five minutes and you already melted her skeleton.

“It—Oh! Forgot to mention that! It uh, it can do that. I don’t know what it means, since I’ve only ever seen it do it once, but it’s fine! It’ll turn back to normal pretty quick I think, at least soon as I saw it like that it turned back to normal—” You heard a muffled voice on the other side of the phone interrupt Sue, and it was silent for a moment before her voice was a little closer to the speaker. “Listen, I need to go. You are doing great so far, I’m sure! You don’t have to worry so much about it, like, we only have a problem if it turns to dust, okay?”

“Turns to dust—what?” you asked, but you heard the phone rub against some clothing.

“Remind me later! Bye!” The three tones followed Sue’s exit, leaving you in silence as you stared at the black puddle of a was-skeleton in a whiskey glass. You awkwardly sat there, phone still pressed to the side of your face for a moment before putting it down. You didn’t know what to make of the situation.

“H-h-how you doing, b-buddy?” You finally asked, turning the glass slightly and looking for any hint of the skeleton within the puddle of darkness. After a tense moment of searching, whiteness built at the top of the liquid, and a skull formed, followed by shoulders. It looked like the skeleton was simply sitting in shoulder-height dark matter, looking at you.

“Ayyy there you are!” You felt a nervous smile make its way on your face. “How you doing there?” It didn’t move. “I-I, uh…I’ll make us lunch, okay? You feeling spaghetti?” you asked, not expecting much of a response but the skeleton actually frowned. “O-or, I can fry up a burger real quick?” You tried again, and this time you got a slight nod. Progress!

“Okie dokie, buddy, I’m gonna bring you over to the kitchen now, just let me know if you are uncomfortable or anything,” you said, carefully picking up the glass. He sunk more into the darkness, keeping just his eyes out of the liquid to watch you. You placed him next to the oven so you could keep track of him in case he did anything else unexpected, but he seemed perfectly intent on watching you as you prepped the stove.

Thankfully you had frozen pre-made patties, so this meal was minimum effort on your end. You fried up the burger and got a bun ready with your usual additions. Every so often you would glance up at the skeleton to double check he wasn’t doing anything new, but he simply watched you. Every time you checked it seemed like more of him was out of the slime. You focused back on the burger, before realizing you forgot something! You opened the fridge and grabbed a piece of cheese, opening it up and getting ready to put it on the patty to melt.

“No cheese, please.”

“Sure thing, buddy,” you replied, putting the cheese to the side before freezing. “Wait, you spoke?” You turned towards the not-so-puddle-y skeleton now, who looked to be kneeling in the glass, leaning his elbows along the rim and resting his chin in his hands.

“Of course.” He rolled his eyes, seeming irritated instead of reserved now. “You were not paying very close attention to me, I tried waving my hands at you but you were too busy with your cooking to notice. I had no choice but to drop the silent act.” You stared wide-eyed at the skeleton as he spoke. He had a voice that reminded you of Sherlock Holmes. Not the Bumbletit Cumbercrotch one though, the Robert Downey, Jr. one.

“O-oh! I’m sorry, buddy!” You apologised, and he raised an…eyebrow-bone? He didn't have an eyebrow but he could make expressions like he did at the very least. “I-I mean—”

“The name is Doctor Gaster, if you insist in trying to call me by something.” He interrupted.

“Gaster? Well I—”

“ _Doctor_ Gaster, unless you carry the title as well..”

“Uh, right— _Doctor_ Gaster… Nice to meet you properly then…” You swallowed, feeling even more awkward now that the “pet skeleton” was now speaking…and apparently has a better education than you did. “Like, an actual doctor or—”

“The burger is burning.” He ignored the start of your question and looked towards the patty, which was just starting to burn. You quickly turned the oven off and used a spatula to drop the burger onto your prepared bun. You glanced at Gaster before putting the burger all together, and pulled out a knife to cut him a section. “I don’t need a lot, I am not terribly hungry at the moment.”

You nodded, cutting a small portion off of the burger and placing it on the smallest plate you had, which was still probably ten times the size you needed. “You…want anything to drink?” Gaster considered for a while, tapping the edge of the glass he was in.

“Some water would be delightful.” He finally settled on, and you looked for a glass small enough for him. The best you could do was a shotglass, but like with everything in your house, was still too big for easy use for him. He must have seen the concern on your face. “That glass will do. I am not as inept as you may think.”

You filled it with water before bringing it and your plates to the coffee table, and coming back to grab Gaster and bringing him over there as well. Placing Gaster’s glencairn next to the plate and shotglass, you sat down on the couch, still too nervous to bother with your burger yet. Gaster glanced up at you, tapping his finger against the glass for a moment before coughing.

“Well? Mind helping me out of this?” He asked, as if it was obvious. Before you could respond he waved a hand with irritation. “Nevermind, I can handle it.” He started pulling himself up out of the glass like how one would get out of the side of a pool. He huffed, resting his upper half of his body over the edge while trying to get his long legs out of the awkwardly shaped cup, and his weight started to unbalance the glass. The glencairn tilted, and by the time you noticed what was happening, the glass hit the table with a loud clang, empty.

You blinked, before you registered emptiness. “Gaster?” You asked, picking up the—thankfully not cracked—glass, and looking around the table.

“ _Doctor_ Gaster.” His voice came from the right, and you saw him laying on his stomach on the ground three feet away, rubbing his head. He got to his knees, before looking at you and crossing his arms. “Of all of the containers I’ve been in, that glass had to be the least practically shaped yet.” He commented as you got off the couch and knelt down in front of him.

“Sorry, it was the only fully transparent glass I had. I wanted to make sure I could keep an eye on you…But how did you end up here?” You offered a hand to him, and he hesitated before half-crawling onto your hand and sitting on your palm, his hands grabbing either side of if to stabilize himself.

“Teleportation. I try not to do it too often as it can be quite a strain on my reserves, though this time I panicked. I suppose your ‘Sue’ didn’t tell you about that?” He was fully solid this time, you didn’t sense anything sticking to your hand. Maybe it had something to do with his mood?

“Not at all.” You carefully brought him back up to the coffee table, and rested your hand close to his plate. He got off surprisingly gracefully for someone who has such lanky limbs and just fell out of a glass.

“I suppose that is to be expected. I did not know her for a terribly long amount of time, and she never required me to break the silent act.” He sat on the plate and crossed his legs, grabbing the still-to-big slice of burger.

“Why the act?” you asked, grabbing your own burger and taking a bite. You watched as Gaster struggled to keep the small burger slice together unless he was holding it sideways, and he then continued to eat it like a watermelon. His mouth was still too small to get all the different parts of the burger in a bite, but he didn’t seem like he was going to complain at the moment. He swallowed and cleared his throat.

“Have you ever acted mute before?” He asked, looking at you. You shook your head, continuing to eat your burger. “A strange phenomenon happens when others see you as mute. A good majority of people will believe you are deaf, or dumb, or maybe even both, and treat you as such. If you want to know the true intentions of someone you never met before, just lead them to believe you do not speak, and you will have your answer.” He put down his burger and looked to the shot glass of water. You were going to grab it for him, but suddenly tiny versions of his hands appeared around it. They worked together to grab it and bring it over to him, and he carefully took a drink out of the oversized cup.

“Huh, I suppose that makes sense. Sorry to make you break your act before you wanted to though.” You figured Gaster must like knowing exactly who he’s dealing with, and you didn’t want to make him uncomfortable in any way. After all, he would be able to tell Sue how his time here was, and you didn’t want to get a bad review.

He finished drinking, and the hands floated the shot glass back to where it was before vanishing. “It is fine. I got the general idea about you at least. Not sure how long I would have put up with you ‘buddy’ nickname anyway.” He shrugged, going back to his burger.

“If it’s anything to consider, I am enjoying having two-sided conversations with you more than the one-sided ones.” You give him a smile, and he nods.

The rest of the meal went by quickly, you didn’t have a lot to say and he didn’t seem to be the conversation starter type of person, but you were slowly getting more comfortable with the small skeleton. At the end of lunch you brought the dishes over to the sink to clean, and Gaster requested to be in the glencairn once more.

“Are you sure? You said it was awkward…” you asked, wanting to make sure. There was no point in him saying in an uncomfortable glass—he was able to teleport, there was no use trying to keep an eye on him anymore.

“No, I said it was the least practically shaped container I have been in. That being said, it is also one of the more comfortable ones I have sat in yet.” He corrected, looking at the glass with a finger to his chin. “So yes, please assist me.” He held out his arms.

You gently grabbed his sides and picked him up enough to place into the glass, and he quickly knelt down to sit in the glencairn. You watched him for a moment, before attending to the dishes.

“Something on your mind?” He asked, watching your hands. You glanced at him again, seeing he was still solid-bodied.

“Well earlier, you were, well…” You wiggled your fingers vaguely, trying to find the proper way to say “slime” without being offensive, since you didn’t know if it was a touchy subject or not.

“Ah, yes, that. I was very stressed for the past…26 hours, give or take. When given an enclosed space I simply couldn’t keep myself together any more. Normally I do not let others see me in such a state, my apologies.” Gaster looked away, looking embarrassed about it.

“Nah man, don’t apologize. If you need to let it out, let it out. You’ve been through a lot, I’m not gonna blame you if you need time to yourself.” You scrubbed the dishes, trying to act as casual as you could. “If you ever feel like going all gooey, just go ahead, I don’t judge. Besides, I know how it is to lose someone. I personally wanted to sleep for the next week, and I kinda did. It did make me feel better in the end, so do what you need to do.” You stacked the dishes and looked over to Gaster, and saw him looking at you. You couldn’t read his face.

“So…You would not be against me taking this time to rest, instead of socializing with you?” He asked, uncertain.

“Of course not Gas—I mean, Doctor Gaster. I can put you in my room and turn off the lights if you need?”

“That won’t be necessary. My eternal gratitude.” And with that, he melted.

You looked at the black tar that was sitting in the glencairn, and finally allowed yourself to wonder what exactly you got yourself into.


End file.
